/*
 * Copyright 2002-2010 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

using System.Xml;
using System.Xml.Schema;

namespace Spring.Util;

/// <summary>
/// XML utility methods.
/// </summary>
/// <author>Aleksandar Seovic</author>
public class XmlUtils
{
    /// <summary>
    /// Gets an appropriate <see cref="System.Xml.XmlReader"/> implementation
    /// for the supplied <see cref="System.IO.Stream"/>.
    /// </summary>
    /// <param name="stream">The XML <see cref="System.IO.Stream"/> that is going to be read.</param>
    /// <param name="schemas">XML schemas that should be used for validation.</param>
    /// <param name="eventHandler">Validation event handler.</param>
    /// <returns>
    /// A validating <see cref="System.Xml.XmlReader"/> implementation.
    /// </returns>
    public static XmlReader CreateValidatingReader(Stream stream, XmlSchemaSet schemas, ValidationEventHandler eventHandler)
    {
        return CreateValidatingReader(stream, new XmlUrlResolver(), schemas, eventHandler);
    }

    /// <summary>
    /// Gets an appropriate <see cref="System.Xml.XmlReader"/> implementation
    /// for the supplied <see cref="System.IO.Stream"/>.
    /// </summary>
    /// <param name="stream">The XML <see cref="System.IO.Stream"/> that is going to be read.</param>
    /// <param name="xmlResolver"><see cref="XmlResolver"/> to be used for resolving external references</param>
    /// <param name="schemas">XML schemas that should be used for validation.</param>
    /// <param name="eventHandler">Validation event handler.</param>
    /// <returns>
    /// A validating <see cref="System.Xml.XmlReader"/> implementation.
    /// </returns>
    public static XmlReader CreateValidatingReader(Stream stream, XmlResolver xmlResolver, XmlSchemaSet schemas, ValidationEventHandler eventHandler)
    {
        lock (typeof(XmlUtils))
        {
            if (!schemas.IsCompiled)
            {
                schemas.Compile();
            }

            XmlReaderSettings settings = new XmlReaderSettings();
            settings.Schemas.XmlResolver = xmlResolver;
            settings.Schemas.Add(schemas);
            settings.ValidationType = ValidationType.Schema;
            if (eventHandler != null)
            {
                settings.ValidationEventHandler += eventHandler;
            }

            return XmlReader.Create(stream, settings);
        }
    }

    /// <summary>
    /// Gets an appropriate <see cref="System.Xml.XmlReader"/> implementation
    /// for the supplied <see cref="System.IO.Stream"/>.
    /// </summary>
    /// <param name="stream">The XML <see cref="System.IO.Stream"/> that is going to be read.</param>
    /// <returns>
    /// A non-validating <see cref="System.Xml.XmlReader"/> implementation.
    /// </returns>
    public static XmlReader CreateReader(Stream stream)
    {
        return XmlReader.Create(stream);
    }
}
